一.解法

https://leetcode-cn.com/problems/ugly-number/
要点：数学
丑数除去所有的2，所有的3，所有的5必为一
用三个while循环即可完成

二.Python实现

class Solution:
    def isUgly(self, num: int) -> bool:
        if num<=0: 
            return False
        while num%2==0:
            num=num/2
        
        while num%3==0:
            num=num/3
        
        while num%5==0:
            num=num/5
        

        return num==1

三.C++实现

class Solution {
public:
    bool isUgly(int num) {

        if(num<=0) return false;


        while(num%2==0){
            num=num/2;
        }
        while(num%3==0){
            num=num/3;
        }
        while(num%5==0){
            num=num/5;
        }

        return num==1;

    }
};

四.java实现

class Solution {
    public boolean isUgly(int num) {
        if (num <= 0) {
            return false;
        }
        int[] factor = new int[]{2,3,5};
        for (int i : factor) {
            while (num%i == 0) {
                num = num/i;
            }
        }
        if (num == 1) {
            return true;
        }
        return false;
    }
}